Carburetor



mi@ 26 we@ O H. ENSIGN GARBURETOR Filed Sept. 50. 1916 2 Sheets-Sheet 2Nrrsn STATES erica.

ORVILLE H. ENSIGN, OF PASADENA, CALIFORNIA.

CARBURETOR.

Application iled September 30, 1916. Serial No. 123,180.

To all whom t may concern.' vention as applied in a carburetor of the Beit known thatI l, ORVILLE H. ENSIGN, type shown in certain of my patentsand a citizen of the United States, residing at applications as follows:Vaporizer, No. Pasadena, in the county of Los Angeles and 1,064,627,patented J une 10, 1913; carbure- State of California, have discoveredand intor, No. 1,064,628, patented June 10, 1913; 60 vented a new anduseful Carburetor, of vaporizer, No. 1,108,727, patented August whichthe following is a specification. 25, 1914; carburetor, No. 1,223,159,patented This invention relates more particularly April 17, 1917,' andfuel adjusting to a carburetor using liquid fuels that are means forinternal combustion motors, No. difhcult to'ignite'when cold. 1,316,149,patented September 16, 1919. 65

An object of the invention is to provide Another object is to furtherperfect the means whereby kerosene and other low Operation of producingthe mixture for the gravity fuels as measured by Baume scale, enginemanifold. and also alcohol, may be satisfactorily used lt is importantthat theproportion of fuel as fuel in internal combustion engines thatto air in the mixture delivered to the engine 70 are constructed andadapted for the ecoshall be constant under all conditions of 4nomic useof gasolene and other high gravity pressure under which air is suppliedto the fuels, Baume scale. g air intake of the carburetor, irrespectiveof 1n carrying out this invention I provide the received air pressure.An object of this a carburetor adapted for the use of heavy invention isto create and maintain such 75 liquid fuel, such for instance askerosene, proportion. This type of carburetor is more enginedistillates, alcohol and the like. particularly intended for heavy dutywork Such fuels do not vaporizeor ignite where air cleaners are usedwith or without readily when the engine is cold, but work hot airstoves. Such air cleaners and stoves satisfactorily after the enginebecomes hot offer such a variable amount of frictional 80 provided heattherefrom or elsewhere isl also resistance to the flow of the air towardthe applied 'to the carburetor. carburetor under changing load; as tocause A principle of this invention is the free a marked variation 0fpressure in the air introduction to the carburetor propo'rtionwhichenters the air intake of the carbuing and mixing passages, of a limitedquanretor. 85 tity of freely igniting fuel, without other Atruecarburetor is designed to work interference with the regular' fuelsupplywith its air intake freely open to the air ,ing operations; sothat no attention upon and so that it will correctly proportion the thepart of the operator is required, after mixture of air and fuel withoutany variastarting with the auxiliary fuel, to maintain tion of airvelocity passing through it. Air 90. the engine under economicaloperation with cleaners or stoves present frictional resistthe heavy orother regular fuel that is diii'iance which creates an irregulardepression culttoignite when cold. instead of depression due to airvelocity An object is to bring about a convenient alone, hence there isneed to eliminate all 4Q economical use of the light fuel employed suchirregular depressions before the air 952- in starting; and in thisregard it is prereaches the fuelsupply.

ferred to minimize the quantity of light fuel With the surface of fuelin the float chamin the charge so as to meet only the lighter ber opento full atmospheric pressure, this demands, such as prevail in normal orusual variation in air pressure dellvered to the atmospheric conditions,and to depend upon carburetorwould cause the proportion of 10Q repeatedchargings where, under more diififuel to air in the mixture to be verymuch cult conditions, one charge is insuiiicient to greater at theheavier, and less at the lighter put the engine into operation en the'regular loads on the engine.

fuel. v An object-of this invention is, therefore,

The invention includes a carburetor com.- to equalize the pressure ofthe air upon the 105 prising a float controlled main fuel chamsurfaceofthe fuel in the float chamber with ber and a freely dischargingauxiliary fuel that of ,the air supplied t0 the airvintake of chamberwithout float open to restricted the carburetor, by thismeans it ispossible gravity How. v g to maintain a constant proportion of fuel toFor convenience I .shall illustrate the-inair under all changes ofload.. 110

-69 description and appended claims.

' that point and also receives by impact the pressure which creates thevelocity of the flowing air; and these added pressures, viz. thepressure of the moving air in the air intake, and the pressure of thevelocity head \of such moving air in lthe intake,. are applied to thesurface of the fuel.

It is desirable that all of the air used to control the proportions o-ffuel and air in the mixture shall be under the same depression as that4delivered to the air intake irrespective ofthe depression caused by theair cleaner or stove; therefore the balancing system must connectbetween the airintalce of the carburetor and the surface of the fuel inthe float chamber, and to the fuel jet; and such connection to the fueljet is preferably arranged so that the amount of such air admitted tothe fuel jet may be regulated; thereby furnishing means for adjustingthe p-roportions of fuel to air throughout the range of the carburetoroperation.

Another object of this invention is to cause this air flow from thebalancing system when once properly adjusted to produce an ejectingaction upon the fuel, delivering it into the main carburetor air streamat the high velocity of theiair fiowing from the balancing system intothe depression caused by carburetor action; and thus when the mixedproportions are changed-by adjusting the fuel orifice it does not effectthe fuel velocity into the carburetor proper; o-r mixture proportion maybe changed as desired by adjusting the quantity of air delivered to thefuel jet; adjusted variations in the quantity of air directed to flowwith the fuel through the fuel ,jet will cause inverse variations in thequantity of fuel delivered per unit of time at any given engine load;while the velocity of the fuel delivered to the carburetor main vairstream varies directly with the amount and the velocity of air which' isadjusted Ito flow to the. fuel jet.

Other objects, advantages and features lof thel invention may appearfrom the accompanying drawings, the subjoined detail The accompanyingdrawings illustrate the invention. f

Figure 1 is an ,enlarged sectional elevation of the carburetor in Fig.5, on irregular line ail-w?, Fig. 3.

Fig. 2 is a sectional elevation on line m2, Figs. 1 and 3, showingconstruction at upper end of the adjusting tube.

F ig. 3 is a reduced plan partly in section on irregular line 'm3-m3, 1,also indicated in Fig. 2.

v Fig. 4 is an axial section of the suction tube at right angles to Fig.1.

Fig. 5 is a diagrammatic elevation of an assembly of the apparatus.

Fig. 6 is a fragmental sectional elevation of the gasoline priming tankon a larger scale than Fig. 5. y

rlhe main fuel chamber l is the usual float chamber for supplying theliquid fuel at a constant level to the suction tube 2 of the carburetor.whence itv passes to the circular vortex chamber 3, andthence to thethrottle tube 4, past` the sump 5 where excessive fuel may accumulate tobe sucked up when the throttle is partly closed.

The suction tube 2 is surrounded by orifice tube v6 that is providedIwith orifice 7 opening from below the liquid level of thel floatchamber l. Orifice ltube 6 forms a fuel well around the suction tube 2over the top of which tube 2 the main or usual liquid-fuel supply flowsfrom tube 6. Said tube 6 is extended up above the level of the top ofthe suction tube2, and is there connected to7 and made to communicatewith, t-he interior of a hollow cover 8 for the float chamber 1. Inother words the orifiee tube 6 is cast integral with, and projectsdownwardly from said hollow cover 8. Said hollow cover forms anauxiliary chamber to temporarily contain a limited charge of auxiliaryliquid fuel, and is provided in itstop with a hole having a lowerthreaded rim 9 and an upper Unthreadedrim 9 lthrough which the-adjustingtube 10 is inserted. Said tube l0 fits to turn freely in the upper rim9', and is threaded into the lower rim 9 at the top ofthe auxiliary7chamber 8 and is extended into the orilice tube 6 and may screw downonto a seat 11 in the floor of the auxiliary chamber 8 which forms astop to limit the travel of the adjusting tube. The adjusting tube formsa suction chamber a above the top of suction tube 2.

The auxiliary chamber 8 isprovided with an inlet 12 into which anauxiliary supply pipe 13 leads from 'a priming tank 14. Said pipe isprovided with a normally closed valve 15 which may be opened by theoperator through the medium of the rod 16, but

which closesautomatieallyso that by a pressure of the hand of theoperator, 4a limited charge of` liquid fuel will be admitted to chamber8 from which it immediately flows through -the constant-ly open outlet17 constituting an auxiliary fuel orifice opening through the wall ofthe adjusting tube 10 yat the bottom of auxiliary chamber 8. Saidchamber 8 is above the. upper end of the fuel passage andsaid orifice isrestricted to allow all the liquid fuel charge to flow from chamber 8into the suction chamber a within a predetermined short time which iscalculated or assumed to be best adapted to the object in view. Inconsequenceof this construction and arrangement. whenever a charge ofgasoline or other` easily ignited liquid fuel is supplied to auxiliarychamber 8 it flows freely through the orifice 17 into the suctionchamber a and finds its Way to the mouth of the suction tube 2, andthence it may pass down through lateral out-let 2 to the vortex mixingchamber 3 and finds its way to the sump 5, so that when the engine isstarted and the throttle butterfly valve 18 is slightly open, the vacuumformed above the throttle 18 may violently draw such liquid fuel throughby-pass tube 19 violently delivering it as a. mist through the startingjet-outlet 20 above said throttle into the engine manifold 21 along withthe air passing through the carburetor and around the throttle.

rlhe air inlet horn 22 is adapted .to receive from a heater 23, heatedair which may or may not have been cleansed. rThe air cleaner 23 may beof any suitable construction.

To maintain operative air pressure on the liquid in chamber 8, an airbalancing Pitot tube 24 leads from the air inlet horn to an air chamber25 surrounding the adjusting tube and formed in the top of chamber 8between the plain upper and the threaded lower-rims 9, 9. Said tube 24communicates through said chamber 25 with air flow adjusting meanscomprising port 26, valve 27 and vertical passage 28 which opens intothe suction chamber 0:.-

Holes to form port 26 and holes to form the passage 28 may be employedin singular or in plurality within the judgment of the constructor.'

A screw 29 limits the lift of the valve 27 under the suction of vortexchamber 3 thus controlling the suction ou orifices 7 and 17.

y, .priming rod 33, to the surface of liquid fuel c in the lmain chamber1, thus supplying to the suction chamber a. aheated supply, and to thesurfaces of the two liquid fuels, a static pressure corresponding tothat of the air entering the mixing chamber through the medium of theair horn 22, thus eliminating the eect of friction on the mixture atvarious speeds and loads -through the heater or the heater and clarifierif both are used as suggested in Fig. 1.

The adjustable tube 10 is provided for adjusting the orifice 7 byscrewing said tube down and up in the threaded hole and is ltept at anydesired position by the Contact spring 34.

The adjusting of the mixture through control of the orifice 7 admits ofproperly determining the mixture proportion without effecting thevelocity of the fuel through the fuel jet which is formed by "thelateral out-v let 2". This fuel velocity is controlled by the adjustmentof air flow which is accomplished by controlling the lift of valve 27'.

The level of the liquid fuel c in the `constant level chamber 1 ismaintained by the 4float 35 through the medium of the lever 36 and thevalve 37, which constitute automatic means for delivering for the fuelpassage of the carburetor, a regulated supply of liquid fuel for anindeterminate period of time .which may be indefinitely prolonged byreother time when it is desired to add fuel to the regular supply fromthe float valve; but said auxiliary supply invariably stops,automatically, as soon as the charge in chamber 3 can pass through theorifice 17. This deflnitely limited period of time may be of slight orof greater duration depending upon the more or less forcible action ofthe suction under different speeds and loads.

The fuel passage of the carburetor comprises the suction tube 2 throughwhich the main and auxiliary liquid fuel passes with some air, and alsoincludes the lateral fuel jet ports 2, the vortex chamber 3, and thehorizontal and vertical limbs 3 and 33 of the exitl from such chamber.

l'n the vortex chamber and exitI therefrom the liquid fuel and air areintimately brought together and carried onward to supply to the engine,the combustible mixture required for its operation.

`When kerosene or other low gravity hydrocarbon fuel is used as the mainliquid fuel supply it is desirable to properly mix water to the mixturein definite proportions` to keep down pre-ignition when the engine isunder speed or load and to economize fuel and increase the horse power,hours per unit of hydrocarbon fuel used.

For this purpose water may be supplied from the water supply tank 38through the water pipe 39 to the constant level Water chamber A4;() andfrom the constant level water chamber 40 through the passage 41 andthrough valve seat 42 controlled by llO valve 43 to the vertical suctionpassage 44 ing packing 48 around the valve 43. Thel vertical watersuction passage is formed in a hollow bolt 49 and said bolt is threadedinto connecting piece 5() by which various fuel supplying elements ofthe carburetor consisting of main constant level chamber 1, vortexmixing chamber 3.bottom mixture passage 3 and lower auxiliary constantlevel chamber 40 are secured together as a whole unit in such a mannerthat these elements may be placed at vario'us relative angles to eachother by relatively revolving them around said bolt 49.

The fuel supplied to the constant level chamber 1 from the supply tank37 through the supply pipe 37" passes through a strainer cap 5.1, andscreen 52 before reaching the valve 37, so that impurities in the fuelwill be precipitated to the floor 53 beneath the screen. l

Air enters the carburetor by way of the opening 54 into the clarifier23', and, beingv freed therein from dust, etc., passes by way of the airtube 55 to the heater 23 around the exhaust pipe 56 and thence by way ofconnection 56 tube 57 and the elbou7 58 to the air inlet horn 22, andthence tangentially into the vortex chamber.

The vortex chamber of the fuel passage is so constructed that thevortical action will produce fromsend to end of the chamber,a-substantially uniform drop of pressure, so thatthe air admittedthrough the tangential air inlet 59 will whirl around the low pressurezone to which the liquid fuel has-passed, and the vortex chamber iscontracted as the frustum of a hollow inverted cone which opensunobstructedly and abruptly into the horizontal mixture passage 3.

The priming tank 14 is provided at the top with a toggle 60 which whenpulled in any direction lifts and' opens the valve 15 to allow a chargeof the light fuel to flow from tank 14 through pipe 13 into the auX-iliary chamber 8. The valve 15 is closed by a spring 61-and the toggle60 is kept tight on its seat .by spring 62. A valve seat 63 performs thedouble purpose of valve seat and part of the union for connecting pipe13.

In practicethe fuel chambers 37 and 14 are supplied with fuel and anindeterminate supply of heavy fuel at once flows to the float chamber tosupply liquid fuel indefinitely to keep the float chamber fuelcont ts atthe required level from which it wllli'be sucked by the engine so as tointermittently flow over the top of the suction valve 15, however,withholds liquid fuel from the vauxiliary determinate charge fuelchamber 8 so that when the engine is operating in the regular way nofuel is drawn from tank 14.

In case the fuel in tank 14 is gasoline or other fuel normally easy toignite when cold, the engine can be started with ease, though theregular fuel in tank 37 be kerosene, alcohol orother fuel normallydifiicult to ignite when cold, butI capable of use when the engine ishot.

The auxiliary fuel chamber 8 is adapted.

to be substituted for the usual cover of the float chamber of certainprevious carburetors and I do not limit v its form to that shown in thedrawings.

The suction tube 2 is enlarged at its top so that a thin annular orifice64 is provided around -the enlarged ton thus to minimize iuctuations ofthe liquid due to jolts and jars on the carburetor and also to reducethe volume of the vacant space between the top of the suction tube andthe top of the liquid in the adjusting tube 10 prior to suction.

The top of the suction tube 2 terminates in a sharpl annular edge 65close to the wall of the adjusting tube 1() so that the capillaryattraction of the adjusting tube upon the liquid between it and I,saidsharp edge exceeds that of the top of athe suction tube and willmaintain a raised rim of liquid around the inner wall of the adjustingtube above the level of the top of the suction tube. By thisconstruction and arrangement great sensitiveness and quick actiondssecured under suction. .A further advantage of this construction andarrangement is that in starting the engine after the automaticallyAclosed needle valve 15 has been temporarily opened, a gasoline chargefrom auxiliary chamber 8 flows at once into the suction tube and on tothe sump without materially mixing with-the fuel from the main floatchamber, and this sump charge will be followed by a mixture of bothfuels sucked by the engine until the charge of lighter fuel is eX-hausted.

The saw kerf 66 in the concave top of tube 2 receives a screw-driver bywhich said tube may be screwed home into the threaded upper bore 67 ofthe connection 50 andremoved therefrom, in assembling and disassemblingthe carburetor.

The upper end of connection 50 is reduced and externally threaded toform a threaded stud 68 extending from a shoulder through the bottom ofthe float bowl or chamber 1. The shoulder 69 at the base of said studfits against the bottom'of said chamber 1.

The orifice tube 6 formed as a downward extension from the cover 8 isinternally threaded at its l'ower end to screw down upon the externallythreaded stud 68 of fitting 50, and on to the bottom of main fuelchamber 1 to clamp it against the shoulder 69 of fitting 50 thus holdingthe cover in place. The auxiliary fuel chamber has a shoulder 70 to seaton the top of main fuel chamber 1, simultaneously with the seating oftube 6 on the bottom of chamber l. The

top of vortex mixing chamber 3 fits an an-l nular seat 71 provided inthe under side of ioat chamber 1 and said,vortex chamber terminates atits lower end in a truncated outlet 72, and has above its discharge end72, an annular shoulder 73 fitting an annular seat- 74 at the inlet tothe passage 3". The horizontal mixture passage member 3" is provided onits under side with a seat for the top of auxiliary ioat chamber 4Q, andthe hollow bolt is inserted through chamber 40, passage 3y and vortexchamber 3 and is screwed into fitting 50. The nut 47 and bolt 49 holdchamber 40, passage 3, vortex chamber 3 and main fuel chamber 1 in fixedassembly, but by loosening nut 47, the parts may be relatively revolvedto fit the carburetor to various structures. rlhe upper end of bolt 49above the port 45 is solid so that the-water is introduced to a mixtureof air and. fuel. V

The needle valve 15 is protected by a screen 7 5 to prevent impuritiesfrom passing from the tank 14 into the auxiliary fuel or high gravitypriming chamber 8 so that the orifice 17 will not become clogged.

1n practice to start the engine into operation the attendant will rstoperate the toggie 60, thus opening the needle valve 15, thus causing acharge'of easily ignited fuel to flow by gravity into chamber 8 andcausing such fuel to fiow through the small oriiice 17 in the adjustingtube to the suction chamber. a, through which it drops onto the elevatedsurface of the heavy gravity fuel around the sharp edge of the suctiontube 2 whence it ows down the suction tube and through the fuel jetformed by lateral passages 2 into the vortex mixingchamber 3 andhorizontal passage 3 of the carburetor to the sump 5 at the bottom ofthe carbureton- Then with vthe butterfly throttle nearly closed, themotor is turned over slowly by the operator, fuel is drawn through t eicy-pass 19 around the throttle 18 and through the idlingor starting jetport 2O and is injected above the throttle valve into the manifold in ajet of ne mist or spray. iThis inist or spray'of ne easily ignited fuelfills the cylinders when ignition occurs in the way usual with such fueland the motor' starts immediately., rhen fuel from theconstant levelsupply chamber iiowsv into suction tube 2 along with the high gravityfuel, and the two are intimately mixed and such mixture of the two fuelspasses through passages 3, 33 and enters the cylinders. Because thelight fuel is intimately mixed with the heavy fuel, and because both areunder the same suction, the two fuels are also accurately proportioned,so that the motor continues t'o operate while still cold, thus allowingthe motor to heat up; giving opportunity for the devices for furnishinghot air to the carburetor from the waste heat of the exhaust gases toget into action toheat the air to 170 F., or more and consequentlysufficient heat is soon supplied to the fuel and air to make it possiblefor the engine or motor to continue operation without the aid of theeasily ignited light fuel from the auxiliary fuel chamber.` At or aboutthat time the light fuel supply in the auxiliary fuel chamber isexhausted and no further /attention in this respect is required. Shouldthe motor be stopped for a short period of time, a slight amount oflight fuel delivered to the auxiliary chamber makes easy starting with awarm motor. After a long coast down a hill, using the motor as a brake,a slight touch of the operator on the toggle 62 will cause a smallquantity of the light fuel to be delivered to the auxiliary chamber soas to put the motor again into action.

Heavy hydrocarbon fuels have a tendency to crack under the heat ofcompression in the motor cylinders, and hence to pre-ignite. Theconflicting forces `ensuing from such pre-ignition are oftentimespowerful enough to loosen bearings, break crank shafts and to otherwisecause damage to the motor. rlhe proper introduction of water is highlydesirable to prevent such pre-ignition, and to this end the constantlevel water chamber 4() at the bottom of the carburetor is provided asshown so that an adjusted mass of water may be introduced with the fuel,but: owing to the elevation of the water. port 45 above the water levelin the doat chamber 40 the water will not be introduced to the mixingvchamber when starting or at light loads, but only after there is someload applied so as to produce suction on the water to lift it thepredetermined distance to cause it to How into the mixing chamber. Afterit begins to How into the mixing chamber it flows under the same suctionand is subject to the same mixing action as the hydrocarbon fuel, andtherefore the water is evenly distributed throughout the inass of themixture with the fuel and air, and the requisite water is applied bythis method to obtain the desired results, viz, the prevention ofpre-ignition and the prevention of carbon` deposits, with the use of aminimum amount of water.

i rlhe'needle valve 15, screen 7 5 and spring 61 are connected togetherwith valve seat 63 as a single unit screwed into the bottom of llO thetank and removable together with the connecting rod 16 by removing thepin that fastens the rod 16 to the tipping toggle 60.

The constant level water supply chamber 40 corresponds in function andoperation to that of the float chamber 1 and need not be specificallydescribed. rIhe valve 43 constitutes means to adjust the proportion ofWater supply and by means of these three supply chambers 1, 8 and 40 incombination with the means set forth for supplying light liquid fuel tothe auxiliary fuel chamber, it becomes possible to put the engine intooperation with minimized attention and maximized satisfactory results.

The hollow truncated conical outlet form of the circular vortex chamberis an improvement over the form shown in my former applications in thatit is a much more exact application of the use of a vortex mixingchamber as a means for correctly metering or measuring out the properamounts of fuel to correspond to different Hows of air.

This result is obtained because this present construction gives to thevortex chamber that is adapted to contain the whirling fluid, a shapemore nearly conforming to the ideal vortical gradient of pressure thusallowing the whirling body of air to assume a condition of varyingdensity extending from the center outward, and this gradient ofpressure. or densities with different velocities of air produces apressure drop at the center which becomes a direct indication ofmetering action both of the air and the fuel.

The amount 'of pressure drop at the center is a measure of the air andalso of the fuel flowing through the vortex chamber. l Particularattention is also directed to the orifice restricted gravity flow thatoccurs through the constantly open outlet 17 whereby the priming liquidis continuously delivered to the suction tube 2 so long as the charge 12in chamber 8 is unexhausted. rIhe two liquid fuels are thereforesupplied in entirely differentmanners and irrespective ofeach other, thesupply of the lighter fuel being continuous from starting until'exhausted, while the heavier fuel is always under the control of thefloat valve; the lighter fuel being simply an addition to the supply ofheavier fuel. By this method I have greatly simplified the apparatus andmade its operation positive from the light fuel starting, to theoperation upon the heavy fuel only.

1. In a carburetor having a. float chamber, a fuel jet, and an airintake, a balancing means to maintain a pressure in the float chamberVcorresponding to that in the air intake of the carburetor, and meansfor j 2. In a carburetor having a float chamber,

a fuel jet and an air intake; a balancing means to maintain a pressurein the, float chamber corresponding to that in the air intake of thecarburetor; and automatic valve means adapted and arranged to close suchbalancing means to the fuel jet and to be lifted against the force ofgravity at a predetermined light load for directing adjustable airsupply from the balancing system of the float chamber to the fuel jetupon increase of load to thereby proportion the fuel to the airthroughout the full range of operation.

3. In a carburetor the combination with a fuel passage of automaticmeans for delivering to such passage a regulated workin supply of liquidfuel for an invdeterminate period of time and fixed unperiod of time;the surface of said predetermined charge of fuel being constantly opento atmospheric pressure; both fuelsl being supplied simultaneouslyduring the predetermined period and the working 4supply continuing afters`uch period.

4. In a carburetor vthe combination with a' fuel passage, of automaticmeans for delivering to such passage a regulated working supply ofliquid fuel for an indeterminate period of time; and fixed unobstructedautomatic means upper end of said fuel vpassage to deliver by gravityand suction to said passage a predetermined charge of liquid within apredetermined period of time, the surface of said fuel being constantlyopen to atmospheric pressure, the fuel during said predetermined periodbeing supplied simulabove the iis taneously with that delivered for anin'- i determinate period.

5. In a carburetor having a float chamber and a cover for said iloatchamber, a main air intake, and a fuel passage; carburetor adjustingmeans consisting of an orifice tube projecting downwardly from saidcover and provided with an orifice submerged under the liquid fuel inthe float chamber and communicating with the fuel passage;adjustment-means for said orilice consisting of an adjusting tubethreaded in the top part of said cover and adapted to regulate theopening of the orifice.; anair valve for admitting air from said airintake to the center of the adjusting tube for ladjusting purposes, andmeans to limit the lift of said air valve.

6. In a carburetor having a fuel passage, regulated means to supplyliquid fuel to said passage for the usual operation of the unobstructedcarburetor; a vented chamber above the upper end of said fuel passageopen to atmospheric pressure and adapted to contain a limited charge ofliquid fuel and provided With a restricted gravity outlet; said chambercommunicating through the. gravity outlet with said fuel passage so thatsaid limited charge will be, by gravity, emptied into the fuel passagethereby to automatically change the fuel supply from unusual to usualoperating conditions.

7 In combination with the mixing chamber of a carburetor; a fuel passageto -deliver fuel to said chamber; a vented auxiliary chamber above saidpassage open to atmospheric pressure and adapted to hold a predeterminedcharge of fuel for startin an engine into operation, and unobstructegravity flow means for conducting fuel from said chamber into said fuelpassageI before delivery to the mixing chamber, said vented chamberbeing empty during normal engine operation and filled by manuallycontrolled means.

8.. A carburetor of the character described consisting of a floatchamber, an air intake, a fuel jet in communication With the lowerportion of the fioat chamber, an air supply leading from the air intaketo the upper portion of the float chamber and direct to the fuel jet. f

In testimony whereof, I have hereunto set myA hand at LosvAngeles,California, this 19th day of September, 1916.

Witness: t

.JAMES R. ToWNsEND.

